A semiconductor structure including a semiconductor substrate having a top surface, one or more group IV semiconductor monocrystalline nanostructures, each having a first and a second extremity defining an axis parallel to the top surface of the semiconductor substrate and separated therefrom by a non-zero distance, each nanostructure having a source structure epitaxially grown on the first extremity and a drain structure epitaxially grown on the second extremity. The epitaxial source and drain structures are made of a group IV semiconductor doped with one or more of Sb and Bi, and optionally one or more of As and P, thereby creating tensile strain in the group IV semiconductor monocrystalline nanostructure.